This invention relates to a sterilization method and an apparatus therefor.
In the past, it has already been practiced to sterilize packing articles such as vessels by using hydrogen peroxide. Specifically, a packing article is, in one method, immersed in hydrogen peroxide and in another method atomized hydrogen peroxide is sprayed to a packing article.
Where the packing article sterilized according to the conventional methods as above is a sheet or takes a sheet-like form, droplets of hydrogen peroxide deposited on the packing article can be removed readily by, for example, blowing hot air to the packing article. However, a cubic packing article having a deep depth or a complicated form faces problems in being removed of the sterilizer. More particularly, hydrogen peroxide can not be removed from part of a cubic packing article sterilized according to the immersing method, and in the case of a cubic packing article sterilized according to the spraying method, removal of hydrogen peroxide from the exterior surface of the packing article is relatively easy but hydrogen peroxide sprayed and deposited on the side wall interior surface, for example, is liable to keep staying in the packing article and it takes a long time to remove such staying hydrogen peroxide.
To cope with these problems, the inventors of the present invention have already proposed a so-called gasification and atomization method as disclosed in Japanese Patent Application Laid-open No. 60-220067. According to this proposal, hydrogen peroxide is atomized into fine droplets, and a hydrogen peroxide film is formed of a small amount of the hydrogen peroxide fine droplets substantially uniformly over the entire surface of even a packing article of a complicated form. The hydrogen peroxide film can be removed efficiently. Thus, this proposal solves the problems encountered in both the conventional methods described previously.
The gasification and atomization method is advantageous as described above but it is still disadvantageous in that because of atomization of the hydrogen peroxide by way of an atomizer nozzle, a pressurizing unit for pressurizing the hydrogen peroxide and an atomization chamber are required, making the overall apparatus complicated, that the atomizer nozzle becomes clogged and the atomization suffers from hunting, resulting in troubles during running of the apparatus and that the consumption of the hydrogen peroxide increases.